The magnetic tunnel junction (MTJ) has emerged as the standard reader technology for present and next generation magnetic recording technology. However, areal density growth in magnetic recording demands a reduction of the reader dimensions resulting in an increasing reader resistance that decreases the signal to noise ratio (SNR). It is anticipated that all metallic current perpendicular to the plane (CPP) spin valve devices will be utilized as readers for 1 Tb/in.2 recording because the resistance area (RA) product is much lower. The challenge of reducing readback noise in future high-density magnetic recording systems highlights the need to investigate alternative readback mechanisms and devices.
One such alternative readback system is the resonance reader, as previously disclosed in US Patent Application Publication 2008/0144232, which is hereby incorporated by reference.